1. Field of the Invention
The present invention relates to a joined structure in which a substrate and a wiring member are connected via an anisotropic conductive film, and a method for producing the joined structure.
2. Description of the Related Art
Conventionally, when a substrate such as a LCD panel, and a PAP panel, and a wiring member such as FPC, COF, and TCP are joined together with an anisotropic conductive film, there are cases where wiring of the wiring member is exposed depending on the position of a resist layer formed in the wiring member. If the wiring member is used by bending in such the condition, there are problems that breaking of a wire may occur, and contaminants (dusts) or the like are included in the bare wiring part, which may cause occurrence of short circuit.
To solve these problems, for example, such a method has been proposed that a bare wiring part is protected with a sealant. Since a device for sealing and a cost thereof are additionally required, it is a current situation that the proposed method is not commonly used.
To this, for example, Japanese Patent Application Laid-Open (JP-A) No. 2002-358026 discloses a method for preventing breaking of wiring by sliding an insulating protective layer (resist layer) of FPC into the inside of a display panel to protect a bare wiring, and some panel manufacturers have put this method into practice.
In this technology, however, the flow of the anisotropic conductive adhesive is stopped by sliding the insulating protective layer into the inside of the display panel, which may cause short circuit, or connection failure occurs as a connection part is not sufficiently compressed during pressure bonding because of the presence of the insulating protective layer.
Moreover, JP-A No. 2003.66479 discloses a method of covering an exposed wiring part of a TAB component by extending and bonding an ACF tape to a solder resist part of the TAB component.
In this technique, however, heat from a heat tool is not easily transferred to the ACF tape extended from the connection part of the display panel and the TAB component, and the ACF tape of this area remains completely uncured. Therefore, there is a problem that durability thereof, such as bending strength, is poor.